Fluid tight closure

ABSTRACT

This invention relates to apparatus for forming a fluid tight closure of an opening in a vessel. The apparatus includes a conduit or fitting adapted to be connected to the vessel, a plug insertable into the conduit and a means for locking the plug in the conduit to prevent the plug from moving out of the conduit. The locking means includes a locking element engageable with the plug to lock it in place. A connector located in a lateral bore through the conduit is connected at one end of the locking element and its other end has a threaded engagement with a nut also located in the lateral bore. Stops are provided at opposite ends of the nut so that upon rotation of the nut to move the connector and locking element between retracted and locking positions, the nut will alternately engage the stops. By making the distance between the stops greater than the length of the nut, the nut is free to move longitudinally between the stops and this construction avoids maintaining close manufacturing tolerances with respect to the distance between the stops. In a preferred embodiment, the inner stop is provided by a shoulder between an outer larger diameter portion of the bore and an inner smaller diameter portion. A seal is carried by the connector to seal between it and the smaller diameter portion of the bore as the connector is reciprocated by turning the nut. Normally the locking element will engage the conduit when in fully retracted position to limit makeup of the nut on the connector and hence limit the outward travel of the connector so as to maintain the seal within the smaller diameter portion of the bore. However, if excessive torque is applied to the nut so as to break the engagement of the connector with the locking element, means are provided to limit further makeup of the nut on the connector and the seal is located so as to remain within the smaller diameter portion of the bore when the nut has a maximum makeup on the connector and both have been displaced outwardly so the nut is in engagement with the outer stop. With this construction, the connector does not rotate thereby enabling it to have a simple bifurcated connection with the locking element and to carry a seal which merely slides along the bore in the conduit without rotation. The seal also isolates the threaded connection from fluids within the vessel.

United States Patent [1 1 Osburn 1 Oct. 23, 1973 FLUID TIGHT CLOSURE.

threaded engagement with a nut also located in the Inventor: Coy D.Osburn, Tulsa, Okla.

Assignee: T. D. Williamson, Inc., Tulsa, Okla.

lateral bore. Stops are provided at opposite ends of the 53Gb that upon'r'aiaudibr the nut to move the connector and locking element betweenretracted and locking positions, the nut will alternately engage theFiled: June 5, 1972 Appl. No.: 259,832

Primary Examiner-Charles A. Ruehl Attorney-W. F. Hyer et al.

[5 7] ABSTRACT stops. By making the distance between the stops greaterthan the length of the nut, the nut is free to move longitudinallybetween the stops and this construction avoids maintaining closemanufacturing to]- erances with respect to the distance between thestops. In .a preferred embodiment, the inner stop is provided by ashoulder between an outer larger diameter portion of the bore and aninner smaller diameter portion. A seal is carried by the connector toseal between it and the smaller diameter portion of the bore as theconnector is reciprocated by turning the nut. Normally the lockingelement will engage the conduit when in fully retracted position tolimit makeup of the nut on the connector and hence limit the outwardtravel of the connector so as to maintain the seal within the smallerdiameter portion of the bore. However, if excessive torque is applied tothe nut so as to break the engagement of the connector with the lockingelement, means are provided to limit further makeup of the nut on theconnector and the seal is located so as to remain within the smallerdiameter portion of the bore when the nut has a maximum makeup on theconnector and both have been displaced outwardly so the nut is inengagement with the outer stop. With this construction, the connectordoes not rotate thereby enabling it to have a simple bifurcatedconnection with the locking element and to carry a seal which merelyslides along the bore in the conduit without rotation. The seal alsoisolates the threaded connection from fluids within the vessel.

11 Claims, 4 Drawing Figures FLUID TIGHT CLOSURE This invention relatesto apparatus for forming a fluid tight closure; and, more particularly,to improvements in that type of apparatus shown in US. Pat. No.2,771,096.

It is sometimes desirable to hot tap a pipeline or vessel through afitting connected to a vessel and having a side opening, such as a tee.Also, after the hot tapping operation has been completed, it may bedesired to plug the fitting. One method of performing this operationinvolves mounting upon the vessel, in the order named and insupreimposed relation, a tee or other side opening conduit, a tappingvalve, and a hot tapping machine. When properly assembled, the machineis operated to run a cutter on the boring bar of the machine through theopen valve and conduit to cut a hole in the portion of the vesselsurrounded by the conduit. Upon retraction of the boring bar and closingthe tapping valve, the tapping machine can be removed and the cutterreplaced by a plug having a suitable releasable connection with theboring bar. The plug is run through the open tapping valve into placeinto the conduit where it is locked in position to form a fluid tightseal across the conduit. Then the tapping valve and the tapping machinecan be removed from the line and replaced by a blind flange. The plugmay be removed from the conduit by reversal of this procedure.

An object of this invention is to provide a plugging apparatus of thistype which is of simplified construction in that it is simpler andcheaper to manufacture.

Another object is toprovide such an apparatus which is less subject tobeing improperly operated so as to cause possibly hazardous conditionsthan the apparatus heretofore being marketed.

Another object is to provide such an apparatus in which a threadedconnection employed to actuate the locking means for the plug is soarranged as to be isolated from working fluid in a pipeline or vesseland therefore is kept cleaner.

These and other objects are accomplished, in accordance with the presentinvention, by apparatus which includes a conduit adapted to be connectedto a vessel,

such as a pipeline, and a plug insertable into the con-.

duit through one end thereof. The plug is locked in place by at leastone locking element mounted on the conduit for reciprocation between aretracted position permitting passage of the plug transversely of thelock ing element and a locking position wherein the locking elementengages the plug to restrain it from moving out of the conduit. Thelocking element is so actuated by rotating a nut which is rotatablydisposed in and slidable longitudinally along a lateral bore through theconduit. The nut has a threaded connection with a connector whichextends to engage the locking element so that as the nut is rotated, itwill reciprocate the connector and the locking element between retractedand locking positions. Stops are also provided in the bore to bealternately engaged by the nut so that as the nut is rotated in onedirection, it will engage one stop and then move the connector andlocking element in one direction and when the nut is rotated in anopposite direction, it will engage the otherstop and then move theconnector and locking element in the opposite direction. In a preferredembodiment, the distance between the stops is greater than the length ofthe nut. This permits one stop to be provided by a bushing screwed intothe outer end of the bore without having to maintain close tolerances onthe degree the bushing is or can be screwed into the bore. The bushingcan be provided with an opening therethrough for receiving a wrench toturn the nut. When the wrench is removed, this opening can be plugged soas to provide further assurance against leakage from the pressurevessel.

With this construction, the connector need not rotate to actuate thelocking element. Therefore it can be connected to the locking element bya simple bifurcated connection, or equivalent, instead of the usualT-head connection. Also, the connector can carry a seal for movementalong the bore to form a seal between the connector and bore withoutrotation of the seal. This seal is preferably located in the boreinwardly of the threaded connection between the connector and nut sothat the latter is protected or isolated from fluids in the vessel.

In a preferred embodiment, the inner stop is provided by a shoulderbetween an outer larger diameter portion of the bore and an innersmaller diameter portion. The seal is carried by the connector to sealbetween it and the smaller diameter position of the bore as theconnector is reciprocated by turning the nut. Normally the lockingelement will engage the conduit when in fully retracted position tolimit makeup of the nut on the connector and hence limit the outwardtravel of the connector so as to maintain the seal within the smallerdiameter portion of the bore. However, if excessive torque is applied tothe nut so as to break the engagement of the connector with the lockingelement, means are provided to limit further makeup of the nut on theconnector and the seal is located so as to remain within the smallerdiameter portion of the bore when the nut has a maximum makeup on theconnector and both have been displaced outwardly so that the nut is inengagement with the outer stop. This prevents escape of fluid from thevessel even when the apparatus has been so broken thereby adding to thesafety of its use even under such adverse circumstances.

In the drawings:

FIG. 1 is an elevational view, partly in section, of a pipeline having atapping machine mounted over a hole therein, and showing the plugconnected to the boring bar of the machine for insertion into theconduit connecting the pipeline and the machine;

FIG. 2 is an enlarged sectional view with the plug inserted into theconduit and locked in placed by locking segments carried by the conduit;

FIG. 3 is a half section taken on the line 33 of FIG.

2 and showing the locking elements in locking position in the plug; and

FIG. 4 is a view similar to FIG. 3 except that locking elements areshown in retracted position and the plug removed.

Referring to the drawings, there is shown in FIG. 1 a pipeline 20adapted to transport fluid under pressure and having a hole 21 throughawall thereof. A pipe stub or nipple 22 is welded to the pipeline insurrounding relation to the hole so as to form a conduit connecting theinterior of the pipeline and a chamber 23 defined by the interior of thetapping valve 24, nipple 25 and the interior of tapping machine 26. Thechamber 23 is elongate and generally cylindrical to permit movement of aplug 27 longitudinally therethrough into locking position within theconduit 22 as shown in FIG. 2.

Plug 27 is removably attached to the boring bar 28 by any suitableconnection such as a plug holder 29 fitting into the lower end of theboring bar and held in place by a retainer rod 30. Plug 27 preferablyhas an opening 31 therethrough containing a check valve 32 which, whenopen, permits equalization of pressures across the plug. During landing,the check valve is held in open position by a push rod 33 abutting thelower end of the retainer rod. However when the latter is removed, thecheck valve will close to prevent further fluid flow across the plug.

The plug is preferably provided with an O-ring type seal situated in agroove in the periphery of the plug and forming a seal between the plugand the flanged fitting of 35.

In order to lock the plug in place in the flanged fitting, the preferredembodiment employs a plurality of locking elements 36 which whenretracted, as in FIG. 4, lie entirely within a peripheral groove 37interiorly of the flanged fitting. These locking elements can be movedinto a peripheral groove 38 in the plug as shown in FIG. 2 to lock thelatter in place.

Actuating means are provided for reciprocating the locking elements asabove indicated. Such means preferably include a connector 39 disposedin a lateral bore 40 extending through the flanged fitting. One end ofthe connector engages a locking element such as by positioning thelocking element between bifurcations 39a and holding it in place by alocking pin 39b.

The other end of the connector has a threaded connection with a nut 41which is rotatably disposed in and slidable longitudinally of anenlarged portion 40a of the bore 40. Means are provided to affordoppositely facing stops engageable by the nut and in this particularembodiment, one stop is provided by an outwardly facing shoulder 42formed at the juncture of the enlarged bore portion 40a and the innersmaller diameter portion 40b and the other stop by the inner end of abushing 43 screwed into the outer end of the bore 40. With thisconstruction, nut 51 essentially floats in the enlarged bore 40a in thatit is free to rotate therein as well as to move longitudinally thereinto whatever degree the distance between the stops exceed the length ofthe nut. It is advantageous to make this distance sufficiently greaterthan the length of the nut such that the manufacturing and assemblytolerances are of minimal importance. Thus, for example, the extent towhich the bushing 43 is screwed into the bore 40a can vary over asubstantial range without interfering with rotation of the nut providedonly that with theoretical maximum makeup of the threaded connectionbetween the bushing and the flanged fitting, the distance between thetwo stops is greater than the length of the nut.

With this construction, a wrench 44 can be inserted through a hole 45through the bushing as shown in FIG. 3 and the nut 41 rotated to, forexample, move the locking elements to retracted position. Usually thefirst increment of rotation of the nut will move it inwardly until itengages shoulder 42. Thereafter, further rotation will cause connector39 and locking element 36 to be retracted to the HS. 4 position.Conversely, when the locking element is to be moved to locking positionas in FIG. 3, the first increment of movement of the nut will beoutwardly to engage the bushing 43 after which the connector and lockingelement will be moved inwardly to the locking position. Thus it will beseen that the clearance or spacing mentioned above provides the nut witha lost motion.

The connector is preferably provided with a seal such as O-ring 46, toseal between the connector and the bore through the flange fitting. Thiseffectively isolates the threaded connection between the nut andconnector from fluids interiorly of the flanged fitting. Also by usingthe bifurcated connection to the locking element, the connector isprevented from rotating as it is reciprocated and this is desirable tothe proper functioning of the seal while the locking elements are beingactuated.

After the wrench has been removed, it is preferred to insert a plug 47in the hole through the bushing to further guard against the possibilityof leaks.

It will be seen from FIG. 4 that normally segments 36 when in fullyretracted position will limit makeup of nut 41 on connector 3? byabutting the inner wall of groove 37. However, if sufficient excessivetorque is applied to shear pin 39b, pressure acting on the inner end ofthe connector can cause it to move outwardly until the outer end of thenut engages the end of bushing 43. Further rotation of the nut willcause it to makeup on the connector until shoulder 39c abuts the innerend of the nut. Seal 46 is positioned inwardly of the threadedconnection sufficiently so that when the above situation occurs, theseal will still be effective in the inner smaller diameter portion 40bof the bore. Thus, even with this extreme situation, leakage of fluidfrom the pressure vessel is not possible.

From the foregoing description of one embodiment of this invention byway of example, it will be seen that this invention is one well adaptedto attain all of the ends and objects hereinabove set forth, togetherwith other advantages which are obvious and which are inherent to theapparatus.

The invention having been described, what is claimed 1. Apparatus forforming a fluid tight closure of an opening in a vessel comprising: aconduit adapted to be connected to a vessel; a plug insertable into theconduit; at least one locking element mounted on the conduit forreciprocation between a retracted position permitting passage of theplug transversely of the locking element and a locking position whereinsaid locking element engages the plug to restrain it from moving out ofthe conduit; actuating means for so reciprocating said locking elementincluding a nut rotatably disposed and longitudinally slidable in alateral bore through the conduit, a connector slidably disposed in saidbore and engaging said locking element to reciprocate the latter uponreciprocation of the connector and also having a threaded connectionwith the nut, means providing inner and outer oppositely facing stopsengageable by the nut so that upon rotation of the nut in one direction,the nut will engage the outer stop and move the connector and lockingelement to locking position and, upon rotation in an opposite direction,the nut will engage the inner stop and move the connector and lockingelement to retracted position, said locking element normally engagingthe conduit when in fully retracted position to limit the makeup of thenut on the connector, means limiting additional makeup of the nut on theconnector when the engagement of the connector with the locking elementis broken, and a seal carried by the connector to seal between saidconnector and bore and located sufficiently inwardly of the threadedconnection as to maintain an effective seal with the bore when the nuthas the maximum makeup on the connector and is engaging the outer stop.

2. The apparatus of claim 1 wherein said bore has an outer largerdiameter portion and an inner smaller diameter portion with an outwardlyfacing shoulder therebetween providing said inner stop.

3. Apparatus for forming a fluid tight closure of an opening in a vesselcomprising: a conduit adapted to be connected to a vessel; a pluginsertable into the conduit; at least one locking element mounted on theconduit for reciprocation between a retracted position permittingpassage of the plug transversely of the locking element and a lockingposition wherein said locking element engages the plug to restrain itfrom moving out of the conduit, actuating means for so reciprocatingsaid locking element including a nut rotatably disposed andlongitudinally slidable in a lateral bore through the conduit, aconnector slidably disposed in said bore and engaging said lockingelement to reciprocate the latter upon reciprocation of the connectorand also having a threaded connection with the nut, and means providingoppositely facing stops engageable by the nut so that upon rotation ofthe nut in one direction, the nut will engage one stop and move theconnector and locking element to locking position and, upon rotation inan opposite direction the nut will engage the other stop and move theconnector and locking element to retracted position.

4. The apparatus of claim 3 wherein a seal is carried by the connectorto seal between the connector and said bore inwardly of the threadedconnection therebetween, wherein the locking element is elongate and isdisposed in an internal groove in the conduit and wherein the engagementof the connector with the locking element limits relative rotationtherebetween whereby the threaded connection is isolated from fluidwithin the conduit and the seal is reciprocated with the connectorwithout rotation. 5. The apparatus of claim 3 wherein said stop meansincludes a shoulder in said bore engageable with one end of the nut anda bushing threaded in the outer end of the bore and engageable with theother end of the nut, the distance between the stops thus provided beingsufficiently greater than the length of the nut that the latter has alost motion sufficient to accommodate variations in manufacturingtolerances.

6. The apparatus of claim 5 wherein said bushing has a threaded holetherethrough allowing insertion of a wrench to rotate the nut, andremovable means plugging said hole.

7. The apparatus of claim 5 wherein said locking element normallyengages the flange when in fully retracted position to limit the makeupof the nut on the connector, means limiting additional makeup of the nuton the connector when the engagement of the connector with the lockingelement is broken, and a seal carried by the connector to seal betweenthe connector and bore and located sufficiently inwardly of the threadedconnection as to maintain an effective seal with the bore when the nuthas the maximum makeup on the connector and is engaging said one stop.

8. An apparatus adapted to be used to form a fluid tight closure of anopening in a vessel comprising: an annular pipe fitting having anoutturned flange; at least one locking element mounted in an internalrecess in the flange for reciprocation between a retracted position insaid recess and a locking position in which at least a portion of thelocking element extends from said recess; and actuating means for soreciprocating said locking element including a nut rotatably disposed inand longitudinally slidable along a lateral bore extending through theflange; a connector in said bore and longitudinally slidable therealong,said connector engaging the locking element to reciprocate the latterupon engagement with the nut; and means providing oppositely facingstops alternately engageable with the nut so that upon rotation of thenut in one direction, the nut will engage one stop and move theconnector and locking element to locking position and, upon rotation inan opposite direction, the nut will engage the other stop and move theconnector and locking element to retracted position.

9. The apparatus of claim 8 wherein said locking element is elongate andis disposed in an elongate recess and wherein the engagement of theconnector with the locking element is formed by the inner end oftheconnector being bifurcated and receiving the locking element between thebifurcations, and a pin extending through the bifurcations and thelocking element.

10. The apparatus of claim 9 wherein a seal is carried by the connectorto form a sliding seal between the connector and bore.

11. The apparatus of claim 8 wherein the stops are provided by anoutwardly facing shoulder in the bore and by a bushing screwed into theouter end of the bore, the distance between the stops being greater thanthe length of the nut so that the latter has a lost motion.

1. Apparatus for forming a fluid tight closure of an opening in a vessel comprising: a conduit adapted to be connected to a vessel; a plug insertable into the conduit; at least one locking element mounted on the conduit for reciprocation between a retracted position permitting passage of the plug transversely of the locking element and a locking position wherein said locking element engages the plug to restrain it from moving out of the conduit; actuating means for so reciprocating said locking element including a nut rotatably disposed and longitudinally slidable in a lateral bore through the conduit, a connector slidably disposed in said bore and engaging said locking element to reciprocate the latter upon reciprocation of the connector and also having a threaded connection with the nut, means providing inner and outer oppositely facing stops engageable by the nuT so that upon rotation of the nut in one direction, the nut will engage the outer stop and move the connector and locking element to locking position and, upon rotation in an opposite direction, the nut will engage the inner stop and move the connector and locking element to retracted position, said locking element normally engaging the conduit when in fully retracted position to limit the makeup of the nut on the connector, means limiting additional makeup of the nut on the connector when the engagement of the connector with the locking element is broken, and a seal carried by the connector to seal between said connector and bore and located sufficiently inwardly of the threaded connection as to maintain an effective seal with the bore when the nut has the maximum makeup on the connector and is engaging the outer stop.
 2. The apparatus of claim 1 wherein said bore has an outer larger diameter portion and an inner smaller diameter portion with an outwardly facing shoulder therebetween providing said inner stop.
 3. Apparatus for forming a fluid tight closure of an opening in a vessel comprising: a conduit adapted to be connected to a vessel; a plug insertable into the conduit; at least one locking element mounted on the conduit for reciprocation between a retracted position permitting passage of the plug transversely of the locking element and a locking position wherein said locking element engages the plug to restrain it from moving out of the conduit, actuating means for so reciprocating said locking element including a nut rotatably disposed and longitudinally slidable in a lateral bore through the conduit, a connector slidably disposed in said bore and engaging said locking element to reciprocate the latter upon reciprocation of the connector and also having a threaded connection with the nut, and means providing oppositely facing stops engageable by the nut so that upon rotation of the nut in one direction, the nut will engage one stop and move the connector and locking element to locking position and, upon rotation in an opposite direction the nut will engage the other stop and move the connector and locking element to retracted position.
 4. The apparatus of claim 3 wherein a seal is carried by the connector to seal between the connector and said bore inwardly of the threaded connection therebetween, wherein the locking element is elongate and is disposed in an internal groove in the conduit and wherein the engagement of the connector with the locking element limits relative rotation therebetween whereby the threaded connection is isolated from fluid within the conduit and the seal is reciprocated with the connector without rotation.
 5. The apparatus of claim 3 wherein said stop means includes a shoulder in said bore engageable with one end of the nut and a bushing threaded in the outer end of the bore and engageable with the other end of the nut, the distance between the stops thus provided being sufficiently greater than the length of the nut that the latter has a lost motion sufficient to accommodate variations in manufacturing tolerances.
 6. The apparatus of claim 5 wherein said bushing has a threaded hole therethrough allowing insertion of a wrench to rotate the nut, and removable means plugging said hole.
 7. The apparatus of claim 5 wherein said locking element normally engages the flange when in fully retracted position to limit the makeup of the nut on the connector, means limiting additional makeup of the nut on the connector when the engagement of the connector with the locking element is broken, and a seal carried by the connector to seal between the connector and bore and located sufficiently inwardly of the threaded connection as to maintain an effective seal with the bore when the nut has the maximum makeup on the connector and is engaging said one stop.
 8. An apparatus adapted to be used to form a fluid tight closure of an opening in a vessel comprising: an annular pipe fitting having an outturned flange; at least one locking element mounteD in an internal recess in the flange for reciprocation between a retracted position in said recess and a locking position in which at least a portion of the locking element extends from said recess; and actuating means for so reciprocating said locking element including a nut rotatably disposed in and longitudinally slidable along a lateral bore extending through the flange; a connector in said bore and longitudinally slidable therealong, said connector engaging the locking element to reciprocate the latter upon engagement with the nut; and means providing oppositely facing stops alternately engageable with the nut so that upon rotation of the nut in one direction, the nut will engage one stop and move the connector and locking element to locking position and, upon rotation in an opposite direction, the nut will engage the other stop and move the connector and locking element to retracted position.
 9. The apparatus of claim 8 wherein said locking element is elongate and is disposed in an elongate recess and wherein the engagement of the connector with the locking element is formed by the inner end of the connector being bifurcated and receiving the locking element between the bifurcations, and a pin extending through the bifurcations and the locking element.
 10. The apparatus of claim 9 wherein a seal is carried by the connector to form a sliding seal between the connector and bore.
 11. The apparatus of claim 8 wherein the stops are provided by an outwardly facing shoulder in the bore and by a bushing screwed into the outer end of the bore, the distance between the stops being greater than the length of the nut so that the latter has a lost motion. 